This invention relates generally to an antenna assembly and, more particularly, to a collapsible, steerable antenna assembly configured for rapid deployment.
Traditionally, to receive an adequate signal from a communication satellite, an antenna had to be securely fitted to a rigid mount which was adjustable in both azimuth and elevation. Later, antennas began being mounted on moving vehicles. These antenna systems were required to be adjustable in elevation sufficiently to suit the latitude of the vehicle. In addition, portable antenna systems also began to develop. These portable systems were also required to be adjustable in elevation sufficient to suit the latitude of the ground at which they were located.
The use of portable antenna systems and other electronic equipment in the field today often requires the positioning of an antenna of substantial size, in order to prevent terrestrial interference and interference from other satellites with signal beings radiated or received by the antenna. In addition, the antenna and its support should be sufficiently compact in the stowed position, so as to not interfere with mobility of the antenna in the field.
Portable antenna systems of the general type mentioned above have been built in the past, but suffer from several disadvantages. These include excessive assembly time, a large number of separate pieces, complex assembly procedures which lead to a loss of parts and unreliability, difficulty of assembly, and the requirement of multiple operators to assemble and disassemble the system.
In addition, these systems have been designed with the primary goal of breaking the unit down into multiple light-weight shipping containers that meet the maximum standards for lower lobe airline shipping. This increases the complexity and lengthens the assembly time of the antenna.
Further, past systems have proved inadequate in their ability to minimize distortion in the antenna dish of the system, due to either assembly technique or parametric distortion under the weight of the dish and other system components.
It is desirable for antenna system components to be as adjustable as possible for positioning and alignment efficiency. There is a continuing need for an antenna system that is highly accurate, yet has high modularity and portability, while remaining simple to assembly.
Accordingly, those skilled in the art have long recognized the need for a collapsible, steerable antenna assembly configured for rapid deployment. The present invention clearly fulfills these and other needs.
Briefly, and in general terms, the present invention resolves the above and other problems by providing a collapsible, steerable antenna assembly configured for rapid deployment. In the present invention, the antenna assembly includes a base mount, a steering controller assembly, an antenna dish, a back frame assembly, a feed leg assembly, a horn mount assembly, and a horn assembly. The base mount supports and positions the steering controller assembly. The controller assembly positions the back frame assembly and includes a plurality of tombstone-shaped steering members that are attached to one another. Hereafter, these steering members will be referred to as tombstone controllers. Each steering member rotates the controller assembly about a separate axis. The back frame assembly includes a center frame, a template assembly, and a feed leg mount. The center frame selectively engages the controller assembly and the antenna dish. The template assembly selectively attaches to the center frame, and includes a plurality of leaves that engage the antenna dish and hinge at an intersection point. The plurality of leaves have a folded transportation state and an unfolded operational state. The feed leg mount attaches to the center frame.
Additionally, in the antenna assembly of the present invention, the antenna dish is supported by the back frame assembly and is utilized for sending and receiving transmission signals. The feed leg assembly includes a main feed leg and side feed legs. The main feed leg connects to and is supported by the feed leg mount of the back frame assembly in order to minimize distortion of the antenna dish due to the weight of the main feed leg. The side feed legs attach to the main feed leg and the template assembly, and facilitate the positioning of the main feed leg with respect to the back frame assembly. The horn mount assembly selectively engages the horn assembly with the main feed leg. The horn assembly is adjustably positioned by the horn mount assembly with respect to the antenna dish.
In a preferred embodiment of the present invention, the base mount comprises a pod mount assembly that includes a plurality of ground engaging support legs, a central shaft, and a telescopic shaft. The pod mount assembly preferably maintains a collapsed state for transportation and a deployed state for operation. Preferably, the central shaft of the pod mount assembly is rotatable between a folded horizontal position and an unfolded vertical position. The central shaft also preferably includes a base and an extendable telescopic shaft that is movable between a stored retracted position and an operational extended position.
Further, in a preferred embodiment, the plurality of ground-engaging support legs rotatably attach to the base of the central shaft. The plurality of ground-engaging support legs have both a folded and deployed position. The central shaft of the mount assembly is configured to rotatably lift the steering controller assembly away from the folded horizontal position to the unfolded vertical position. The telescopic shaft is configured to lift the steering controller assembly away from the stored retracted position to the operational extended position.
In another preferred embodiment of the present invention, the steering controller assembly includes three tombstone-shaped steering members, a horizontal tombstone controller, a vertical tombstone controller, and a transmission beam tombstone controller. The horizontal tombstone controls the azimuth of the antenna dish; the vertical tombstone controls the elevation of the antenna dish; and the transmission beam tombstone controls the polarization of the antenna dish.
In a preferred aspect of the present invention, the side feed legs connect to the main feed leg and to the template. The side feed legs act as long turnbuckles. The turnbuckle adjustments are used to modify the effective length of the side feed legs, and thereby adjust the elevation angle of the main feed leg and the associated position of the horn assembly with respect to the antenna dish. Preferably, the side feed legs each include telescoping extensions housed within the side feed legs. The telescoping extensions each have a stored retracted position and an operational extended position.
In another preferred aspect of the present invention, the main feed leg includes an amplifier frame, a feed strut, a quick release latch, an uplink amplifier, a flexible wave guide, a signal cable, and a wave guide quick disconnect assembly. The feed strut is selectively attachable to the amplifier frame via the quick release latch. The uplink amplifier is secured to the amplifier frame where it amplifies the transmission signal. The flexible wave guide attaches to the uplink amplifier and directs the transmission signal to the horn assembly. The signal cable attaches to the amplifier and carries the transmission signal to the amplifier. The wave guide quick disconnect assembly selectively separates the wave guide from the amplifier. In this manner, the quick release latch and wave guide quick disconnect assembly allow the main feed leg components to quickly and efficiently separate for increased modularity and transportability without the use of tools. In other embodiments of this invention the amplifier (and thus, the signal cable) might reside at other locations on the invention other than on the amplifier frame, but this would not affect the ability of the main feed leg components to quickly and efficiently separate.
In yet another preferred aspect of the present invention, the horn mount assembly further includes a feed strut attachment plate, wave guide mount circular clamp, a horn circular clamp, a flexible wave guide mount, a Z-axis jack screw, and a Y-Z tilt jack screw. The horn mount assembly connects the horn assembly to the main feed leg through the feed strut attachment plate. The horn assembly and orthomode transducer connect to the horn mount assembly through the wave guide mount circular clamp, the horn circular clamp, and the flexible wave guide mount. The wave guide mount circular clamp provides a connection bracket for the flexible wave guide mount. The horn circular clamp provides a connection bracket for the horn assembly. The orthomode transducer provides a connection bracket for the flexible wave guide mount and a mount for attaching a rejection filter and satellite receivers/downconverter to the horn assembly.
The Z-axis jack screw facilitates translation of the horn mount assembly and the connected horn assembly along the horn transmission beam axis in order to modify the focal length with respect to the centerpoint of illumination of the antenna dish. As used herein, the centerpoint of illumination of the antenna dish is defined as the intersection of the transmission beam from the horn assembly and the dish. The axis from the horn assembly to the centerpoint of illumination of the antenna dish is defined as the horn transmission beam axis. The axis along which the reflected beam traverses from the centerpoint of illumination out to an infinite distance from the antenna dish is defined as the transmission beam axis. The Y-Z tilt jack screw facilitates rotation of the horn mount assembly and the connected horn assembly in a vertical plane, as defined by the horn transmission beam axis and a vertical axis. The configuration listed above is an offset reflector dish. In other embodiments of this invention, other types of dish and other types of reflector arrangements may be used with the steering head and mount assembly.
In another preferred embodiment of the present invention, the antenna assembly further includes a horn-mounted polarization drive assembly for adjusting the polar orientation of the horn assembly with respect to the antenna dish. This motion is independent from the polarization motion provided by the steering head. Preferably, the drive assembly includes a manual drive, a torque plate, a flex drive torque cable, and an adjustment knob. The manual drive is selectively securable to the horn mount assembly. The torque plate is used to apply torque to the wave guide mount that is operatively associated with the horn assembly. The first end of the torque cable connects to the manual drive and the second end of the cable terminates in an adjustment knob. Manipulating the adjustment knob facilitates a manual polarization adjustment of the horn assembly from any remote location that is within the length of the flex drive torque cable. Preferably, the manual drive is a manual worm drive. The polarization drive assembly facilitates remote manual polarity adjustment of the horn assembly while the antenna system is actively transmitting a signal for increased signal alignment efficiency. This allows the ease of polarity adjustment in situations where the backframe and antenna assembly are to be set up without the steering head as used in fixed antenna installations.
In still another preferred embodiment of the present invention, the antenna assembly further includes a quick disconnect assembly for efficient and accurate connectability of the wave guide to the amplifier. The wave guide end fitting of the wave guide is configured to seat against the mating wave guide fitting on the amplifier. The quick disconnect assembly includes a receiver that is secured to the mating wave guide fitting. The receiver is configured to correspondingly house the wave guide end fitting of the flexible wave guide upon selective insertion of the wave guide end fitting into the receiver. The receiver itself further includes a contact face, a fork end brace, and a threaded aperture.
The quick disconnect assembly further includes a fork that has a contact face, a base portion, and two legs with leg ends. The base portion includes a securement knob with threadings. Rotation of the securement knob advances or retracts the threadings. To secure the quick disconnect assembly, the ends of the legs are inserted under the fork-end brace of the receiver, and the fork legs are rotated about the fork end brace. This causes the contact face of the fork to seat against the contact face of the receiver. Tightening of the securement knob then causes the threadings of the fork to secure into the threaded aperture of the receiver, thereby securing the fork against the receiver.
In a preferred embodiment quick disconnect assembly, the receiver includes a plurality of depressions, and the fork legs include a plurality of protrusions that are positioned and configured to correspondingly mate with the depressions in the receiver. In this manner, the ends of the legs are inserted under the fork-end brace of the receiver and the fork legs are rotated about the fork end brace. This causes the protrusions on the fork legs to seat into the depressions in the receiver, thereby causing evenly distributed pressure between the wave guide end fitting of the flexible wave guide and the mating wave guide fitting on the amplifier. Thus, the flexible wave guide is secured to the mating wave guide fitting on the amplifier.
In yet another preferred embodiment of the present invention, the antenna assembly further includes an alignment jig for positioning the horn assembly with respect to the antenna dish. The alignment jig includes a central hub, a plurality of jig arms connecting to the central hub, and a reference ring suspended from the central hub. The plurality of jig arms are selectively securable to the antenna dish. The reference ring is positioned and oriented with respect to the antenna dish to provide a target for the positioning of the horn assembly. The horn assembly correspondingly mates against the reference ring when the horn assembly is properly positioned and oriented.
In still another preferred embodiment of the present invention, the antenna assembly further includes a laser alignment device for positioning the horn mount assembly with respect to the antenna dish. The centerpoint of illumination of the antenna dish is defined as the intersection of the transmission beam from the horn assembly and the dish. The horn mount assembly provides a mount for the horn assembly to transmit a signal along an axis towards the antenna dish, which is defined as the horn transmission beam axis. The laser alignment device has an elongated body that includes attachment mounts for attaching to the horn mount assembly. The device also has a laser emitter contained within the body that projects a laser along the horn transmission beam axis. The laser alignment device facilitates aligning the horn mount assembly (to which the horn assembly attaches), with respect to the centerpoint of illumination of the antenna dish. This is accomplished by using the laser projection along the horn transmission beam axis, and does not require the antenna system to be actively transmitting.
In another preferred aspect of the present invention, the laser alignment device of the antenna system further includes a mock horn disc that corresponds dimensionally to the horn assembly in both size and position when the laser sighting device is mounted on the horn mount assembly. The mock horn disc of the laser alignment device allows the alignment jig to be used simultaneously with the laser alignment device.
In another preferred embodiment of the present invention, the antenna assembly further includes a transmission field sighting device for sighting potential obstructions within the transmission beam of an antenna dish. The sighting device includes a sighting tube that aligns parallel with the transmission beam axis of the antenna dish, and an attachment bracket for securing the sighting tube to the antenna system. In this manner, viewing through the sighting tube of the transmission field sighting device allows determination of whether any obstructions exist within the transmission beam of the antenna dish, thereby facilitating obstruction-free positioning and orientation of the antenna system.
In another preferred aspect of the present invention, the dish assembly is a multi-piece assembly that is detachable into a reduced-sized collapsed state. The antenna dish is constructed of a plurality of detachable, approximately wedge-shaped members. Preferably, the dish assembly further includes stiffening members to help minimize parametric distortions.
In one preferred embodiment of the present invention, the dish assembly, back frame assembly, rotary steering assembly, and collapsible mount assembly are deployable by a single person. Preferably, the steerable antenna assembly is collapsible, rapidly deployable, having very few parts, and is inexpensive compared to other types of known antenna systems.